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butalik [34]
1 year ago
7

10. When Raphael solved the system below by using the method of elimination, he changed the second equationto -8x – 2y = -2. Wha

t property justifies this manipulation?8x + 3y = 74x + y = 1
Mathematics
1 answer:
Alex17521 [72]1 year ago
5 0

\begin{gathered} 8x+3y=7\ldots eqn(1) \\ 4x+y=1\ldots.eqn(2) \end{gathered}

The property that justifies multiplying through eqn(2) by -2 is;

the rationalization to align the coefficients of x in both equations with a view to eliminating the terms in x.

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In a clinical test with 2161 subjects, 1214 showed improvement from the treatment. Find the margin of error for the 95% confiden
Vlad [161]

Answer:

The margin of error for the 95% confidence interval used to estimate the population proportion is of 0.0209.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of \pi, and a confidence level of 1-\alpha, we have the following confidence interval of proportions.

\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}

In which

z is the z-score that has a p-value of 1 - \frac{\alpha}{2}.

The margin of error is of:

M = z\sqrt{\frac{\pi(1-\pi)}{n}}

In a clinical test with 2161 subjects, 1214 showed improvement from the treatment.

This means that n = 2161, \pi = \frac{1214}{2161} = 0.5618

95% confidence level

So \alpha = 0.05, z is the value of Z that has a p-value of 1 - \frac{0.05}{2} = 0.975, so Z = 1.96.

Margin of error:

M = z\sqrt{\frac{\pi(1-\pi)}{n}}

M = 1.96\sqrt{\frac{0.5618*0.4382}{2161}}

M = 0.0209

The margin of error for the 95% confidence interval used to estimate the population proportion is of 0.0209.

4 0
3 years ago
HELP ME PLEASE THIS MEANS A LOT TO ME
nevsk [136]

Answer:

I cannot see the screen. Write it out please and I will answer.

Step-by-step explanation:

7 0
3 years ago
Answer all please, thank you :)
prisoha [69]

The angles in a triangle add up to 180 degrees.  That's the same sum as a linear pair, which we get when two lines cross.

1. 180 - 65 - 45 = 70

Answer: 70°

2. 180 - 90 - 35 = 55

Answer: 55°

3. 180 - 120 = 180 - 50 - x

x = 70

Answer: 70°

6 0
3 years ago
Read 2 more answers
The following functions give the populations of four towns with time tt in years.
expeople1 [14]

Solution :

Transforming given equations :

1)\ P = 600( 1 + \dfrac{12}{100})^t\\\\2)\ P = 1000( 1 + \dfrac{3}{100})^t\\\\3)\ P = 200( 1 + \dfrac{8}{100})^t\\\\4)\ P = 900( 1 - \dfrac{10}{100})^t

From above equations we can see that equation 1) has largest percentage growth rate and the percent growth rate is 12% .

Hence, this is the required solution.

6 0
3 years ago
Read 2 more answers
Factorise each of the following.
Alborosie

I will do (a) only.

6rt - 3st + 6ru - 3su

6rt - 3st = 3t(2r - s)

6ru - 3su = 3u(2r - s)

Answer: (3t + 3u)(2r - s)

Do the rest likewise.

7 0
3 years ago
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